Energy Transformed National Research Flagship, CSIRO, GPO Box 1538, Hobart, TAS 7001, Australia.
Appl Microbiol Biotechnol. 2012 Mar;93(5):2215-31. doi: 10.1007/s00253-011-3856-4. Epub 2012 Jan 18.
Heterotrophic growth of thraustochytrids has potential in co-producing a feedstock for biodiesel and long-chain (LC, ≥C(20)) omega-3 oils. Biodiscovery of thraustochytrids from Tasmania (temperate) and Queensland (tropical), Australia, covered a biogeographic range of habitats including fresh, brackish, and marine waters. A total of 36 thraustochytrid strains were isolated and separated into eight chemotaxonomic groups (A-H) based on fatty acid (FA) and sterol composition which clustered closely with four different genera obtained by 18S rDNA molecular identification. Differences in the relative proportions (%FA) of long-chain C(20), C(22), omega-3, and omega-6 polyunsaturated fatty acids (PUFA), including docosahexaenoic acid (DHA), docosapentaenoic acid, arachidonic acid, eicosapentaenoic acid (EPA), and saturated FA, as well as the presence of odd-chain PUFA (OC-PUFA) were the major factors influencing the separation of these groups. OC-PUFA were detected in temperate strains of groups A, B, and C (Schizochytrium and Thraustochytrium). Group D (Ulkenia) had high omega-3 LC-PUFA (53% total fatty acids (TFA)) and EPA up to 11.2% TFA. Strains from groups E and F (Aurantiochytrium) contained DHA levels of 50-61% TFA after 7 days of growth in basal medium at 20 °C. Groups G and H (Aurantiochytrium) strains had high levels of 15:0 (20-30% TFA) and the sum of saturated FA was in the range of 32-51%. β,β-Carotene, canthaxanthin, and astaxanthin were identified in selected strains. Phylogenetic and chemotaxonomic groupings demonstrated similar patterns for the majority of strains. Our results demonstrate the potential of these new Australian thraustochytrids for the production of biodiesel in addition to omega-3 LC-PUFA-rich oils.
异养生长的硫球藻在生产生物柴油和长链（LC，≥C（20））ω-3 油的原料方面具有潜力。在澳大利亚塔斯马尼亚（温带）和昆士兰（热带）进行的硫球藻生物多样性调查覆盖了包括淡水、半咸水和海水在内的多种栖息地。共分离出 36 株硫球藻菌株，并根据脂肪酸（FA）和甾醇组成将其分为八个化学分类群（A-H），这些分类群与通过 18S rDNA 分子鉴定获得的四个不同属聚类非常接近。长链 C（20）、C（22）、ω-3 和 ω-6 多不饱和脂肪酸（PUFA），包括二十二碳六烯酸（DHA）、二十二碳五烯酸、花生四烯酸、二十碳五烯酸（EPA）和饱和 FA 的相对比例（%FA）以及奇数链 PUFA（OC-PUFA）的存在是影响这些群分离的主要因素。OC-PUFA 存在于 A、B 和 C 组（裂殖壶菌属和硫球藻属）的温带菌株中。组 D（Ulkenia）的 ω-3 LC-PUFA 含量较高（总脂肪酸（TFA）的 53%），EPA 高达 TFA 的 11.2%。在 20°C 下在基础培养基中生长 7 天后，来自 E 和 F 组（雨生红球藻属）的菌株的 DHA 水平达到 TFA 的 50-61%。G 和 H 组（雨生红球藻属）的菌株具有较高的 15:0（TFA 的 20-30%）和饱和 FA 的总和在 32-51%的范围内。在选定的菌株中鉴定出 β，β-胡萝卜素、角黄素和虾青素。大多数菌株的系统发育和化学分类分组显示出相似的模式。我们的结果表明，这些新的澳大利亚硫球藻除了生产富含 ω-3 LC-PUFA 的油外，还具有生产生物柴油的潜力。
